Low-humidity environments are increasingly required in recent production processes. The low-humidity environment, i.e., dry atmosphere is used as an environment essential in the manufacture of lithium-based batteries.
A dry room for maintaining a predetermined atmosphere is employed to improve the quality and yield of products manufactured in the low-humidity environment. In a broad meaning, the dry room is a low-humidity room in which the amount of moisture in air is controlled to a certain value or less. Particularly, a room in which the indoor dew point temperature is −10° C. or lower is called as the dry room. The dry room is distinguished from a low-humidity room with an absolute humidity of about 10 to 30%.
The dry room is used in not only lithium-based battery factories but also hygroscopic stitching fiber production processes, lyophilization food companies, vehicle environment laboratories, laboratories requiring low-humidity conditions, factories, etc.
FIG. 1 is a perspective view schematically illustrating a dehumidifying process of a related art dehumidifier.
If the operation of the dehumidifier is started, a processing fan 12 and a regenerative fan 20 are driven. External gas (external air) is sucked by the driving of the processing fan 12 so as to be transferred to a pre-cooler 10. The pre-cooler 10 performs operations of removing foreign matters, cooling air, etc. The pre-cooler 10 removes moisture contained in the sucked air. The air having the moisture removed by the pre-cooler 10 is transferred to the processing fan 12. In this case, air exhausted through a return flow path (return duct) of a dry room (not shown) is also transferred to the processing fan 12.
The air passing through the processing fan 12 is supplied to dehumidification and fuzzy regions 14a and 14c of a dehumidifying rotor 14. The dehumidifying rotor 14 is belt-connected to a motor 16. The air having humidity removed by the humidification region 14a passes through an after-cooler (not shown) and is then supplied to the dry room (not shown). The humidity of the dry room (not shown) is maintained as a predetermined value by the supplied air, and work is performed in the dry room (not shown). A portion of the air is exhausted to the outside of the dry room (not shown), and the rest of the air is transferred to the processing fan 12 through the return flow path (not shown).
Meanwhile, the air supplied to the fuzzy region 14c of the dehumidifying rotor 14 passes through the fuzzy region 14c and is then transferred to a regenerative heater 18. The regenerative heater 18 heats the transferred air. The heated air is transferred to a regeneration region 14b of the dehumidifying rotor 14. The moisture sucked in the dehumidifying rotor 14 is removed by the regeneration region 14b. The air passing through the regeneration region 14b is exhausted to the outside of the dehumidifier by the regenerative fan 20.
In the related art dehumidifier operated as described above, the regenerative heater 18 always heats the air to an equal regeneration temperature (i.e., 180° C.). In other words, the regenerative heater 18 unconditionally heats the air to the regeneration temperature of 180 so that the dehumidifying rotor 14 achieves maximum performance regardless of indoor humidity, etc. in the dry room.
However, if the regenerative heater 18 is unconditionally operated, the consumption of power is unnecessarily increased, and therefore, operational cost is increased.
Further, the regenerative heater 18 is operated to the same regeneration temperature all through the four seasons, and therefore, the lifetime of the regenerative heater 18 is reduced.